In general, a construction machine such as a hydraulic excavator as a typical example of a construction machine is constituted by an automotive lower traveling structure, an upper revolving structure rotatably mounted on the lower traveling structure and a working mechanism provided on a front side of the upper revolving structure, capable of moving upward/downward.
Here, the hydraulic excavator includes a small-sized hydraulic excavator for performing a work in a narrow work site or the like. For example, this small-sized hydraulic excavator is called a super small turning type or a rear super small turning type and is formed in a compact manner so that at least a rear side is substantially accommodated in a vehicle width of the lower traveling structure when the upper revolving structure performs a turning operation.
The upper revolving structure of the small-sized hydraulic excavator has a revolving frame forming a support structural body, an engine mounted in a laterally placed state extending in the left and right direction on the rear side of the revolving frame, a cooling fan having a plurality of blades around a hub member located on one side of the engine in the left and right direction and mounted on an output shaft of the engine and generating cooling air by being driven by the engine, a hydraulic pump provided on the other side of the engine in the left and right direction and supplying the hydraulic oil to a hydraulic actuator by being driven by the engine, and a heat exchanging device including an oil cooler provided on the revolving frame so as to face the cooling fan and cooling the hydraulic oil and a radiator for cooling coolant of the engine (Patent Document 1).
Here, the heat exchanging device is constituted to surround the cooling fan by providing a shroud so that the cooling air by the cooling fan can be sufficiently supplied to the oil cooler and the radiator. In this case, an arrangement relation among the cooling fan, the oil cooler, and the radiator is made such that the cooling fan is arranged at a position away from the oil cooler and the radiator by a predetermined dimension so that the rotating cooling fan does not interfere with the oil cooler and the radiator and also the cooling air by the cooling fan is supplied to the entirety of the oil cooler and the radiator (Patent Document 2).